Biochemical changes and in‐vitro protein digestibility of the endosperm of germinating dolichos lablab

Abstract

Abstract A gradual decrease was noted in total protein, soluble protein and protein fractions such as albumin, globulin, prolamine andglutelin in the endosperm of Dolichos lablab L germinated for 8 days. Prolamine showed a maximum decrease of 85% whereas only a 25% decrease was noted in the globulin fraction. Both acid and alkaline protease activities increased during germination, and the acid protease activity was consistently higher than the alkaline protease activity throughout. Electrophoretic studies showed that high molecular weight polypeptide bands disappeared with the appearance of new low molecular weight polypeptide bands in the endosperm proteins of the germinating seeds. Total phenolics and tannin contents and trypsin inhibitory activity also increased during the progressive germination. Germination increased the in‐vitro protein digestibility of the endosperm of Dolichos lablab in the presence of proteolytic enzymes like pepsin, trypsin and pancreatin. It showed a negative but non‐significant correlation with trypsin inhibitory activity, phenolics and tannin contents. Amylase activity also increased gradually up to the sixth day of germination which coincided with the increase in the reducing sugars.